Electrical couplings are devices that connect two shorter electrical conduits together in order to form a single, longer electrical conduit. Conventionally, non-threaded conduit couplings employ set screws that rotate into a housing that receives two ends of the conduit. Each screw engages one end of the conduit to hold it in place forming a single longer conduit. Though functional, these couplings involve a multi-step process to connect the two conduits together.
Original attempts at an alternative conduit coupling were unsuccessful. One attempt included two round pieces of tubing. One of the pieces had two straight sprigged pieces of metal which stuck out slightly beyond the edge of the tubing. At the end of the straight sprigged metal was an outward bend on each. The other piece of tubing had two slots cut out of it about one eighth of an inch from the edge so when pushed together with the other piece of tubing the bends on the edges of the sprigged metal will lock it together. This did not work because the two pieces of conduit would not fit flush together. In a similar design, one of the pieces of tubing had two pieces of straight metal that had slight aberrations at the end of them. These two pieces of metal stuck out about one half inch from the edge of the tubing. The other piece of round tubing had two pieces of metal that were attached to the inside of the tubing, so that when the other round piece of tubing was pushed up against it, the two straight pieces of metal would be inside the tubing. Twisting the tubes in opposite directions would lock them together. Again, however, the conduits would not fit flush up against each other.
Another failed attempt also consisted of two pieces of tubing. One tube had a smaller piece of tubing that stuck out of it about one inch. On the inside of the small tubing there were two drilled holes and inside the holes were two push buttons. The other tube had two bends that flared out and two holes drilled in it. The purpose of this was that when the two pieces of tubing came together, the bends allowed the buttons to be pushed in and the holes where the buttons would expand and lock into place. This version was too big and too bulky and did not make the conduits fit flush together.
Another failed attempt included using two different sizes of tubing; one that was larger than the other. The larger tubing was just a round tubing with some of it removed by machining its inside and middle. The other two pieces of tubing were smaller and flat on one side and had long straight cuts on the other side. These two pieces fit into each side of the larger tubing until the flat side abutted against the edge of the larger tubing. Pushing the conduit in on each side of the larger tubing would lock the conduit in. Pulling the conduit out would cause the smaller tubing to get tighter. Again the conduits would not fit flush up against each other. Similarly, this version was modified by rolling the large tube two times on the outside to make two small ribs on the inside. This was meant to hold the smaller pieces in on each side. The other two pieces of tubing were smaller and flat on one side and had long straight cuts on their other side. These two pieces fit into each side of the larger tubing until the flat side butts up against the edge of the larger tubing. Again, pushing the conduit in on each side should lock the conduit in. Again, however, the conduits did not fit flush up against each other.
The present disclosure includes an electrical conduit coupling configured to receive the ends of two separate conduits, and easily and securely join them together without any need for fasteners, set screws, tools, or multiple steps. An illustrative embodiment includes a casing having a larger diameter than the conduits. The casing has opposing open ends each configured to receive a corresponding end (or end portion) of a conduit. Illustratively, the casing may include a center crimp that reduces its diameter to about the diameter of the conduit, and to which the ends of the conduits are engagable thereby creating a continuous pass-through from one conduit to another. The casing may also have outer crimp rings located on each side of the center crimp ring also reducing the diameter of the casing at those locations. These outer crimp rings may be used as retainers for locks that fit in the casing and are located between the casing and the conduit. There is illustratively one lock for each end of the conduit. Each lock slides into one end of the casing engaging one of the outer crimp rings.
In an illustrative embodiment of each lock, a plurality of fingers extends from a cylindrical flange that fits around the periphery of the end of the conduit and the interior surface of the casing. Each finger includes an illustrative rise on its exterior periphery configured to engage one of the outer crimp rings. An illustrative finger tip extends inward toward the conduit surface to provide a grip on the conduit. A tab surface located on the interior of each finger is likewise configured to engage the surface of the conduit. This causes each finger to bias outwardly from the central axis of the lock when the conduit is inserted to assist the rise in engaging the crimp. The conduit pushes against the tab surfaces causing each finger to slightly separate. This separation allows the conduit to proceed past the finger tips and continue sliding in the casing until the conduit engages the center crimp. By separating the fingers, the rise on each finger wedges against the outer crimp ring to help hold the conduit securely in place. Each conduit operates in the same manner on each side of the casing to form the single longer conduit. These aforedescribed structures mean the installer may push a conduit into each lock on each side of the casing—that is all. There are no additional steps to be performed by the installer, such as fastening down multiple set screws.
To release the conduits from the coupling, the lock holding the coupling is pulled slightly from the casing to further wedge the rise on each finger against its outer crimp ring. Once this tight wedge is created, the lock is pushed back in against the casing. This creates enough give to allow the conduit to be pulled straight out from the lock. So long as the lock is held against the casing while the conduit is being pulled, the conduit will slide out of the lock. No tools or other equipment are needed to accomplish this, making it a much simpler task saving time and money on a construction job that may require many conduits to be coupled together.
Another illustrative embodiment of the present disclosure provides an electrical conduit coupling comprising a casing and first and second locks. The casing includes opposed first and second openings, and first, second and third crimps. The first, second and third crimps are formed in the casing to provide a smaller diameter in the casing at each crimp. The first lock includes a flange and a plurality of fingers extending from the flange. Each finger includes a first surface and second surface opposite the first surface. A rise portion is located on the first surface of each finger and a tab surface extends from the second surface of each finger. Each finger includes a tip surface extending opposite the first surface and from the second surface. The first lock is configured to be received in the first opening of the casing and the second lock is configured to be received in the second opening of the casing. The rise on each first surface of each finger of the first lock is configured to engage the first crimp of the casing and each first surface of each finger of the second lock is configured to engage the third crimp of the casing. The second crimp has first and second opposed sides wherein the first side is configured to engage a first conduit that is inserted into the first opening of the casing such that the first conduit has an outer surface that engages the rise portion and tip of each finger of the first lock. Likewise, the second side is configured to engage a second conduit that is inserted into the second opening of the casing wherein the second conduit has an outer surface that engages the rise portion and tip of each finger of the second lock.
In the above and other embodiments, the electrical conduit coupling may further comprise: the fingers of the first lock having at least a portion that is separated from each other, and wherein the fingers of the second lock have at least a portion that is separated from each other; the fingers of the first lock extend from its flange in a cylindrical pattern forming a passageway concentric with the first opening of the casing and the fingers of the second lock extend from its flange in a cylindrical pattern forming a passageway concentric with the second opening of the casing; each of the first, second and third crimps are circularly formed in the casing; each finger of the first lock includes the tip that extends from end of second surface toward the passageway and configured to engage a surface on the conduit.
Another illustrative embodiment of the present disclosure includes a method of coupling two conduits together, the method comprises the steps of: providing a casing having opposed first and second openings, and first, second and third crimps, wherein the first, second and third crimps are formed in the casing to provide a smaller diameter in the casing at each crimp, a first lock that includes a flange and a plurality of fingers extending from the flange, wherein each finger includes a first surface and second surface opposite the first surface, wherein a rise portion is located on the first surface of each finger and a tab surface extending from the second surface of each finger, herein each finger includes a tip surface extending opposite the first surface and from the second surface, wherein the first lock is located in the first opening of the casing and the second lock is located in the second opening of the casing, wherein the rise on each first surface of each finger of the first lock is engagable with the first crimp of the casing and each first surface of each finger of the second lock is engagable with the third crimp of the casing, wherein the second crimp has first and second opposed sides; inserting a first conduit into the first opening of the casing and engaging the tab surface and tip of each finger of the first lock to move each finger toward the first crimp until the conduit engages the first surface of the second crimp; and inserting a second conduit into the second opening of the casing and engaging the tab surface and tip of each finger of the second lock to move each finger toward the third crimp until the conduit engages the second surface of the second crimp.
Additional features and advantages of the coupling assembly will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the coupling assembly as presently perceived.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the apparatus and method of coupling electrical conduit, and such exemplification is not to be construed as limiting the scope of the apparatus and method of coupling electrical conduit in any manner.